Forget the centuriesold image taught in school textbooks that Chagas disease would affect almost exclusively rural populations, like those in northern Minas Gerais and southern Bahia, who live in humble mud houses that barbers might attract the insect.
In a way, the disease described by the medical doctor Carlos Chagas in 1909, caused by the protozoan he studied in a wagon converted into a laboratory and which he called Trypanosoma cruzi, is no longer the same.
“His profile has changed a lot,” says cardiologist José Antônio Marin Neto, a professor at the USP School of Medicine (University of São Paulo) in Ribeirão Preto, in central São Paulo. Truth. And the change says a lot about these times when people travel from one place to another with the utmost ease and often have problems with their luggage. Even times when nature is increasingly being devastated. “Now Chagas disease is cosmopolitan,” observes the doctor.
To give you an idea, the most conservative estimates suggest that about 300,000 people in the United States are living with it. Just as there are many Chagas people in almost every country in Europe there are more than 40,000 in Spain alone! —, in Japan, Australia, New Zealand and Canada, not to mention the one or other case that pops up here and there in the most diverse metropolises of the world.
Result: There are between 16 and 18 million infected people across continents. Of these, nine out of ten people go undetected, and since the disease is also passed from mother to child, the PAHO (Pan American Health Organization) calculates that 8,000 babies are born with Trypanosoma cruzi every year just looking at America . But fortunately, this type of transmission is declining and represents the minority of cases.
“Most unfortunate is that only 1% of those infected with protozoa receive treatment throughout their lives,” notes Professor Marin. For the rest, the disease develops secretly for twenty, thirty years. After that time, a proportion of people will end up on the transplant waiting list with hearts so enlarged and muscles so limp that they are unable to keep beating.
Last week, the Brazilian Society of Cardiology published a new guideline for Chagas disease, an update of the first version published 11 years ago, but this time with a special focus on the damage trypanosoma inflicts on the heart muscle, how to recognize it and of course how to treat them.
It took more than a year of intense effort by a group of doctors gathering the latest evidence in this regard before the document was presented during the World Congress of Cardiology held in Rio de Janeiro last week. “It is extremely important work because Chagas disease has put doctors working in urban areas in a difficult situation, as many are unaware of its specificities,” says the professor.
The difference when you swallow the insect
The text of the guideline, which Professor Marin helped draft, draws attention to the following: The disease is not always transmitted after the barber, who loves to suck our blood, bites someone and then defecates. In fact, it’s not the spike that transmits anything, it just opens a passage.
“However, the entry point for trypanosoma through the ingestion of contaminated food has become increasingly frequent and of concern,” says the cardiologist. “The insect, which plays the role of carrier of this protrozoan, is often crushed together with the sugar cane in the preparation of garapa, or together with the açaí pulp,” he explains. In other countries, the same thing happens with other foods.
The oral mode of transmission is of great importance as it is more malignant. “When the barber bites someone, the trypanosoma is in the feces, which he leaves on that spot afterwards. But the skin not only has fewer protozoa in the faeces, it also offers resistance and the hole made in it ultimately allows only a small amount of this infectious agent to enter. That is something completely different than swallowing a whole or part of a crushed insect,” the doctor compares.
The juice with the little insect passed in the blender offers a huge load of the annoying trypanosoma. He doesn’t even expect to get into the stomach where acid wouldn’t be friendly. “The mucous membranes of the mouth and esophagus are very permeable. They pass easily and in large numbers,” says the professor.
Patients can then die in a few days in front of stunned doctors. “If the transmission occurs through the bite, people often don’t even notice it. The organism can get rid of the protozoa without us having to do anything,” explains Marin.
new vectors
When we talk about barbers, that’s the nickname of at least half a dozen insects. “But today there are many more insects that can transmit the disease agenda,” informs the cardiologist.
In nature, the ancient barbers were in balance with wild animals such as the opossum, which may have the protozoa in their organism.
“But the devastation of forests means that these species are approaching urban areas and that other insects found in cities have an opportunity to sting one of these contaminated wild animals and thus acquire the trypanosoma, which is later shed in the feces becomes. “
how is the disease
Falling into the bloodstream, the protozoan that was in the barber’s feces circulates until it reaches organs like the intestines and heart, where it lodges.
While this is happening, that is, while a good amount of the protozoa are migrating through the blood, the person in the acute phase of the disease, which can last a little over a week, presents with a fever, feels faint, and has a headache. You can even mistake this whole breakdown for a more severe flu. There is swelling all over the body, which can be clearly seen from the swollen eyes.
But in some people, the disease becomes chronic. And, well installed in the heart, the protozoan, without making a fuss, causes changes in the anatomy of this organ, since it makes its function progressively worse.
“The heart is getting weaker and weaker,” explains the doctor. “That’s what we call heart failure. But it doesn’t stop there: these patients also have a very clear tendency to form blood clots, or thrombi, which can travel to the brain and cause a stroke.”
There are also changes in rhythm, that is, the beats can be gutted or, on the contrary, extremely slow. “There are even cases where the patient alternates between times when the heart rate is too fast and too slow. This puts his life in danger of sudden death.”
Professor Marin recalls that this was one aspect that caught Carlos Chagas’ attention when he transferred to a post in rural Minas Gerais to investigate cases of malaria. There he began studying insects, in which he identified the protozoa.
Later, a woman took her 2yearold daughter, Berenice, to the doctor. In her blood, the paramedic found trypanosoma in humans for the first time. as dr When Chagas inquired about the child’s father, he was told that he had dropped dead. I heard the same answer from other people in the area: many had relatives who seemed to have died out of nowhere. And it was this disease that today can be in any corner.
take life
It would be great if every case were caught in the first few days, in the acute phase, while the person has what appear to be flulike symptoms and are persistent the fever usually doesn’t go away in less than a week. She should do a serological test or even a PCR to suspect if the malaise occurred four to fifteen days after visiting an endemic region and the occurrence of outbreaks or other close cases in relatives and colleagues.
At this point it is still possible to use specific medicines, distributed free of charge by the Ministry of Health, to help the organism kill the protozoa. But they no longer work later when the infection becomes chronic.
In this case, the cardiologist can treat, for example, heart failure and arrhythmia when they occur and try to stop them from progressing.
“A concern of the new guideline is that the cardiologist fights the stigma of people with Chagas disease,” says Professor Marin. “Prejudice stems from a time when this disease prevented the person from even having a job. Today we are categorical: if the person has Chagas’ disease without symptoms such as fatigue, they have an annual checkup and this disease has not yet affected their heart, they can do anything, even fly a plane or compete in sports.”
For example, Berenice, the little girl in whom Carlos Chagas first discovered the disease in 1909, was followed by cardiologists until she died of another cause at the age of 70. Now the therapeutic possibilities of medicine to cope with these cases are even greater, as long as … Well, as long as everyone knows that the risk of contagion is always and everywhere in the world, and does not neglect it.